Program timer



Oct. 2, 1962 A. c. ALBEE 3,055,864

PROGRAM TIMER v Filed Sept. 3, 1959 3 Sheets-Sheet 1 fie. 2.

III

INVENT OR ARTHUR C. ALBEE wad/ ATTORNEY Oct. 2, 1962 A. c. ALBEE3,056,864

PROGRAM TIMER Filed Sept. 3, 1959 5 Sheets-Sheet 2 INVENTOR ARTHUR C.ALBEE A. C. ALBEE PROGRAM TIMER Oct. 2, 1962 3 Sheets-Sheet 3 FiledSept. 3, 1959 90 as 86' 90 93 I 106 92 United States Patent f 3,056,864PRQGRAM TMER Arthur C. Albee, Burbank, Calif, assignor to RadioCorporation of America, a corporation of Delaware Filed Sept. 3, 1959,Ser. No. 837,864 9 Claims. (@l. 200-46) This invention relates toprogram timers to provide switching facilities for a predeterminedseries of desired events, and is useful, for example, as a mechanismwhich provides switching facilities for a flight programming unitserving as an autopilot control of ballistic missiles.

Program timing mechanisms generally utilize perforated tape or filmwhich control switches in a certain predetermined order of operation.The present invention is one wherein a perforated film is used tooperate a plurality of switch blades or fingers in the order ofperforation of the film. The film transport mechanism utilizes a drivesprocket, a supply reel, and a takeup reel, and is reversible inoperation, since each reel is provided with its own over-runningclutches to provide the proper, variable takeup drive and hold-backtension when the fun"- tions of the reels are reversed. The plurality ofaligned switching blades or fingers are spring-biased and, uponencountering a perforation in the film, are moved into contact withrespectively associated pins to close an electrical circuit. Thesprocket is provided with grooves under the longitudinal portions of thefilm containing the perforations to accommodate the movement of theswitch blades to enable them to make the necessary electrical contacts.The mechanism is driven by a motor through a series of reduction gearsto provide the desired film speed for the sprocket and for driving thetakeup reels.

The principal object of the invention is to provide an improved timingmechanism in which the closing of a plurality of electrical circuits ina predetermined order is facilitated.

Another object of the invention is to provide an improved program timingmechanism which is rugged and may be used in fast-moving airborne units,such as ballistic missiles.

A further object of the invention is to provide an improved mechanismfor making electrical circuits in a predetermined order, which iscontained in a minimum of space, and which is particularly reliable forairborne units.

A better understanding of this invention may be had from the followingdetailed description, when read in connection with the accompanyingdrawings, in which:

FIG. 1 is a perspective view showing the over-all appearance of thecasing housing the invention;

FIG. 2 is an enlarged, sectional view taken along the line 22 of FIG. 1;

FIG. 3 is an elevational view taken along the line 3-3 of FIG. 2;

FIG. 4 is an enlarged, detail view of the switch contact elements;

FIG. 5 is a fragmentary, sectional view taken along the line 5-5 of FIG.4;

FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG. 3;

FIG. 7 is a reduced, cross-sectional view taken along the line 77 ofFIG. 6;

FIG. 8 is a cross-sectional view taken along the line 8-8 of FIG. 6; and

'FIG. 9 is a plan view taken along the line 9-9 of FIG. 4.

Referring, now, to the drawings in which the same reference numeralsindicate like elements, a film transport and switching mechanism iscontained in a rectangular casing 5 having mounting extensions 6 and 6and side closing and bearing plates 7 and 8. Within the casing mechanisma pair of opposite-acting,

3,056,864 Patented Oct. 2, 1962 5 is a motor 10 having a shaft 11 onwhich is mounted a small driving gear 12. The gear 12 is meshed with alarger gear 13 which rotates with a gear 14 in mesh with a gear 15 onthe shaft of a gear 16 in mesh with a gear 17 driving the gears 18 and19. The gear 19 has a gear 22 on its shaft which also drives a sprocket23. A series of gears 25, 26, and 27 drive the shaft of a reel 30, whilegears 31, 32, and 33 drive the shaft of a reel 35. Through the gearsjust described, the sprocket and reels are provided with the desiredrotational speed for advancing a program film 38 at the desired linearspeed.

As shown in FIG. 3, the film 38 is advanced in the direction of thearrow from reel 35 around a guide roller 39 over the toothed sprocket23, and around a guide roller 40 to reel 30. Upon reversal of the motor,the film passes from reel 30 to reel 35- over the same path but in thereverse direction. The sprocket, gears, and reels are mounted on shafts,some of which have hearings in a frame 42 and some in the side plates 7and 8, three bearings 43, 44, and 45 being shown in side plate 8. Aplate 47 covers these bearings.

Mounted on the inner portion or plate 59 of the frame 42 is a block 52having a groove 53 therein in which is a cable 54 for the electricalconductors from the switches and to the motor. (See FIG. 9.) Fastened tothe block 52 is a multiple switch which includes a metal switch block 56attached to mounting blocks 52 by screws 57 and 58. The switch block 56has a plurality of grooves 60 therein (see FIG. 5) through all of whichpasses a pivot pin 61 on which are mounted a plurality of contactfingers or blades 63 having rounded film contact portions 64 and whichare under bias of a plurality of springs 66 fastened to one side of theswitch block 56 by a plate 67 and screws 70. The rounded ends 64 areadapted to pass through apertures 83 in the film to drop into grooves 84in the sprocket 23. This movement permits the other ends of the bladesto make electrical contacts.

Mounted to one side of the block 56 is an L-shaped plastic contact pinsupport 68 which is fastened to the block 56 by screws 69. The lowerportion 71 of the plastic pin support accommodates a plurality of pins72 the lower ends 73 of which extend below the lower surface of the pinmount 71, and the upper ends of which extend to substantially the upperedge of the pin mount 68. To the upper ends of the pins '72, electricalconductors 75 are connected, the conductors being positioned along theupper surface of the block 56 and thence entering the cable 54, as shownin FIG. 9. The conductors 75 pass through notches 76 in the upper edgeof the pin mount 68. The block 56 is provided with stepped grooves 78and 81' for accommodating the cable 54.

To maintain the conductors and cable in position and to cover the upperends of the pins 72, this portion of the block is plasticized to formthe sheet 80, which is held at one end by an undercut groove 81 in theblock 56, and which extends over the conductors and pins at its otherend 82. The cable 54 shown in FIG. 9 passes into a terminal box 86 towhich a cable 87 may be connected for external connection of the timer.

As mentioned above, the film transport mechanism may be reversed toadvance the fihn in either direction. To accomplish this, each film reelhas included in its drive over-running clutches made up of rollers 86'for one clutch of reel 30, and rollers 88 for one clutch of reel 35 (seeFIG. 3). In FIG. 6, rollers 86' are shown within one end of a cylinder90, and rollers 86 within the other end of the cylinder, the cylinderhaving an annular recess 91 therein. Rollers 86 are mounted on a spider92, and rollers 86' are mounted on a spider 93. Spider 93 is fixed tothe drive shaft 105, While spider 92 is pinned to inner plate 50 by apin 94 and is free of the shaft 105. The pin ends 100 of the respectiverollers 86 and 86' are mounted in elongated, over-sized slots in thespiders 92 and 93, respectively, and are biased .in a linear directionby springs 95 and 96, one end of each spring being in contact with aroller 86 or 86, and the other end of each spring being mounted on abracket 98 or 99, as the case may be, for the respective springs 95 and96. A square cam 97 for reel 30 and a similar cam '97 for reel 35 (seeFIG. 3) move the rollers radially as they move linearly to obtain abinding action between the inner surface of the cylinder and therespective cams.

Thus, for reel 30 to function as a takeup reel, the drive shaft 105rotates the cylinder 90 through spider 93, since the springs 96 urge therollers 86 toward one end of the respective flat surfaces of the squarecam 97 to bind the inner surface of the cylinder to the cam. Sincespider 92 is free of the shaft 105, it remains stationary inasmuch as itis pinned to the plate 50.

To provide the desired speed variation between the cylinder 90, whichrotates at a constant speed, and the speed of the reel 30, which variesas the film roll increases in diameter when used as a takeup reel, asplit fiber ring having sections 1 and 102 (see FIG. 7) is positioned inthe recess 91 of the cylinder. The sections 101 and 102 are urgedoutwardly by resilient plugs or springs 103 and 104, the sections beingheld and limited in movement by pins 106 in oversized holes in thesections 101 and 102. In this manner, sufficient friction is obtainedbetween the reel and the sections 101 and 102 to drive the reel and takeup the film, but the reel can slip to accommodate its change in speed.

Now, when the reel shaft is reversed and the reel is serving as a supplyreel, the cylinder '90 is locked to spider 92 by reason of the springs95 urging the rollers 86 to the ends of the flat sides of theirassociated square cam 97. Since the spider 92 is held stationary, thecylinder 90 then is held stationary. However, the spider 93 can rotatefreely within the cylinder, since the rollers 86' are urged toward thecenter of the fiat surfaces of their associated square cam. With thecylinder stationary, the reel must now slip on the fiber sections 101and 102 which now provide the desired hold-back tension in the film.Therefore, the two over-running clutches for each reel, together withthe friction drive for each reel through the fiber sections, provide thedesired, variable speed takeup reel action and the desired supply reelhold-back action to permit identical film advancement drives in eitherone of the two opposite directions.

I claim:

1. A multiple switching device comprising a sprocket adapted to advancea perforated film having perforations along different transverse areasthereof, a pair of combination takeup and supply reels for said film,reversible driving means for driving said reels, said reel driving meansincluding a pair of opposite-acting clutch devices for each of saidreels, one clutch device of each said pair being effective to transmitpower from said driving means to its associated reel and the otherclutch device of each said pair being eflfective to cause a drag to beapplied to its associated reel depending upon the direction of drive ofsaid reel driving means, means for driving said sprocket atsubstantially constant speed, a plurality of film actuable contactswitch blades pivoted adjacent said film, one end of each of said bladesbeing disposed for contact with a 6 diiferent one of said transverseareas of said film and being responsive to film perforations at therespective ones of said areas, a plurality of contact elementscorresponding in number to and each associated with a different one ofsaid switch blades, and conductors from said contact elements forconnection of said switching device to devices to be actuated whencontact is made between any of said blades and their respective saidcontact elements.

2. A multiple switching device comprising a sprocket adapted to advancea perforated film having perforations along different transverse areasthereof, a pair of combination takeup and supply reels for said film,reversible driving means for driving said reels, said reel driving meansincluding a pair of opposite-acting clutch devices for each of saidreels, each of said clutch devices comprising an over-running clutch,one for driving its reel as a takeup reel and the other for placing adrag on its said reel during the time it functions as a supply reel,means for driving said sprocket at substantially constant speed, aplurality of film actuable contact switch blades pivoted adjacent saidfilm, one end of each of said blades being disposed for contact with adifferent one of said transverse areas of said film and being responsiveto film perforations at the respective ones of said areas, a pluralityof contact elements corresponding in number to and each associated witha diiferent one of said switch blades, and conductors from said contactelements for connection of said switching device to devices to beactuated when contact is made between any of said blades and theirrespective said contact elements.

3. A multiple switching device in accordance with claim 2 in which meansare positioned within each said reel for providing a predetermineddriving friction to its reel and providing a predetermined drag theretowhen its said reel functions as a supply reel.

4. A program timing device comprising an enclosing casing and withinsaid casing a film sprocket adapted to advance a perforated film havingperforations along different transverse areas thereof, reversible motormeans for driving said sprocket at a substantially constant speed in oneor the other of two opposite directions to correspondingly advance saidfilm, a pair of film reels adapted to alternately function as takeup andsupply reels depending upon the direction of rotation of said sprocket,a plurality of gears between said motor means and said sprocket and saidfilm reels for driving said sprocket and reels in correspondence witheach other, a shaft for each of said reels driven by said gears, meansincluding a pair of opposite-acting clutch devices on each of saidshafts coupling each of said reels to their respective said shafts, oneclutch device of each said pair being effective to transmit power fromits associated one of said shafts to its associated reel, and the otherclutch device of each said pair being effective to cause a drag to beapplied to its associated reel, in each case depending upon thedirection of drive of said motor, a plurality of switch blades pivotedadjacent said sprocket, one end of each of said blades being disposedfor contact with said film along a different one of said transverseareas thereof, said sprocket having grooves therein over which theperforations in said film pass, a plurality of contact elementscorresponding in number to and each associated with a different one ofsaid switch blades and adapted to be contacted by the other ends of saidswitch blades when said first-mentioned ends pass through saidperforations and into said grooves, a plurality of conductors attachedto said contact elements and extending externally of said casing, andmeans for hermetically enclosing said contact elements and saidconductors.

5. A program timing device comprising an enclosing casing and withinsaid casing a film sprocket adapted to advance a perforated film havingperforations along different transverse areas thereof, reversible motormeans for driving said sprocket at a substantially constant speed in oneor the other of two opposite directions to correspondingly advance saidfilm, a pair of film reels adapted to alternately function as takeup andsupply reels depending upon the direction of rotation of said sprocket,a plurality of gears between said motor means and said sprocket and saidfilm reels for driving said sprocket and reels, a shaft for each of saidreels driven by said gears, means including a pair of opposite-actingclutch devices on each of said shafts coupling each of said reels totheir respective said shafts, said clutch devices comprising over- 5running clutches, one of said clutches connecting its associated reel toits shaft when functioning as a takeup reel, and the other of saidclutches holding said lastnamed reel shaft stationary when saidassociated reel functions as a supply reel, a plurality of switch bladespivoted adjacent said sprocket, one end of each of said blades beingdisposed for contact with said film along a different one of saidtransverse areas thereof, said sprocket having grooves therein overwhich the perforations in said film pass, a plurality of contactelements corresponding in number to and each associated with a differentone of said switch blades and adapted to be contacted by the other endsof said switch blades when said first-mentioned ends pass through saidperforations and into said grooves, a plurality of conductors attachedto said contact elements and extending externally of said casing, andmeans for hermetically enclosing said contact elements and saidconductors.

6. A program timing device comprising an enclosing casing and withinsaid casing a film sprocket adapted to advance a perforated film havingperforations along different transverse areas thereof, reversible motormeans for driving said sprocket at a substantially constant speed in oneor the other of two opposite directions to correspondingly advance saidfilm, a pair of film reels adapted to alternately function as takeup andsupply reels depending upon the direction of rotation of said sprocket,a plurality of gears between said motor means and said sprocket and saidfilm reels for driving said sprocket and reels, a shaft for each of saidreels driven by said gears, means including a pair of opposite-actingclutch devices on each of said shafts coupling each of said reels totheir respective said shafts, means positioned on each of said reelshafts for frictionally driving said reels when functioning as takeupreels and for exerting a predetermined amount of drag on said reels whenfunctioning as supply reels, a plurality of switch blades pivotedadjacent said sprocket, one end of each of said blades being disposedfor contact with said film along a different one of said transverseareas thereof, said sprocket having grooves therein over which theperforations in said film pass, a plurality of contact elementscorresponding in number to and each associated with a different one ofsaid switch blades and adapted to be contacted by the other ends of saidswitch blades when said first-mentioned ends pass through saidperforations and into said grooves, a plurality of conductors attachedto said contact elements and extending externally of said casing, andmeans for hermetically enclosing said contact elements and saidconductors.

7. A multiple switching device comprising a sprocket adapted to advancea perforated film having perforations along different transverse areasthereof, a pair of combination takeup and supply reels for said film,reversible driving means for driving said reels concurrently in one orthe other of two opposite directions, first and second opposite-actingclutches interposed between said driving means and one of said reels,third and fourth oppositeacting clutches interposed between said drivingmeans and the other of said reels, means for applying drag to therespective said reels, said first clutch being efiective to transmitpower from said driving means to said one reel and said fourth clutchbeing effective to cause said drag applying means to apply drag to saidother reel in response to operation of said driving means to drive saidreels concurrently in said one direction, said second and third clutchesthen being inactive, and said third clutch being effective to transmitpower from said driving means to said other reel and said second clutchbeing effective to cause said drag applying means to apply drag to saidone reel in response to operation of said driving means to drive saidreels concurrently in said other direction, said first and fourthclutches then being inactive, means for driving said sprocket atsubstantially constant speed, a plurality of film actuable contactswitch blades pivoted adjacent said film, one end of each of said bladesbeing disposed for contact with a different one of said transverse areasof said film and being responsive to film perforations at the respectiveones of said areas, a plurality of contact elements corresponding innumber to and each associated with a diiferent one of said switchblades, and conductors from said contact elements for connection of saidswitching device to devices to be actuated when contact is made betweenany of said blades and their respective said contact elements.

8. A program timing device comprising an enclosing casing and withinsaid casing a film sprocket adapted to advance a perforated film havingperforations along diiferent transverse areas thereof, reversible motormeans for driving said sprocket at a substantially constant speed in oneor the other of two opposite directions to correspondingly advance saidfilm, a pair of film reels adapted to alternately function as takeup andsupply reels depending upon the direction of rotation of said sprocket,a plurality of gears between said motor means and said sprocket and saidfilm reels for driving said sprocket and said reels in correspondencewith each other, a shaft for each of said reels driven by said gears, afirst friction coupling member and first and second opposite-actingclutches on one of said shafts for coupling said one shaft to one ofsaid reels, a second friction coupling member and third and fourthopposite-acting clutches on the other of said shafts for coupling saidother shaft to the other of said reels, said first clutch beingeffective to transmit power from said one shaft to said first frictioncoupling member to thereby drive said one reel and said fourth clutchbeing eflective to cause said second friction coupling member to applydrag to said other reel all in response to operation of said motor meansin one direction, said second and third clutches then being inactive,and said third clutch being eifective to transmit power from said othershaft to said second friction member to thereby drive said other reeland said second clutch being effective to cause said second frictioncoupling member to apply drag to said first reel in response tooperation of said motor means in the reverse direction, said first andfourth clutches then being inactive, a plurality of switch bladespivoted adjacent said sprocket, one end of each of said blades beingdisposed for contact with said film along a diiferent one of saidtransverse areas thereof, said sprocket having grooves therein overwhich the perforations in said film pass, a plurality of contactelements corresponding in number to and each associated with a diiferentone of said switch blades and adapted to be contacted by the other endsof said switch blades when said first mentioned ends pass through saidperforations and into said grooves, a plurality of conductors attachedto said contact elements and extending externally of said casing, andmeans for hermetically enclosing said contact elements and saidconductors.

9. In combination, a sprocket adapted to advance a film, a pair ofcombination takeup and supply reels for said film, reversible drivingmeans for driving said sprocket and said reels concurrently in one orthe other of two opposite directions, first and second opposite-actingclutches interposed between said driving means and one of said reels,third and fourth opposite-acting clutches interposed between saiddriving means and the other of said reels, means for applying drag tothe respective said reels, said first clutch being effective to transmitpower from said driving means to said one reel and said fourth clutchbeing effective to cause said drag applying means to apply drag to saidother reel in response to operation of said driving means to drive saidreels concurrently in said one direction, said second and third clutchthen being inactive, and said third clutch being effective to transmitpower from said driving means to said other reel and said second clutchbeing effective to cause said drag applying means to apply drag to saidone reel in response References Cited in the file of this patent UNITEDSTATES PATENTS Lester Dec. 19, 1933 r s Parkingson Mar. Debrie Dec.Osborn Jan. Cami-as Nov. Bole Sept. James Nov Frankel Apr

